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I have a 2006 rx8 that starts fine on a cold start.
After it runs for 3 to 5 minutes it dies.
Wont start back up until it cools all the way back off.
Doesnt even make it to running temperature.
Anybody have this problem before.
Thanks.
Sounds like that engine is toast (because it won't restart when warm) , but let's go through the usual checks: what do the spark plugs look like? How old are the ignition coils and are they working? Any vacuum leaks? What intake is on there and its not OEM what if you put back the original one?
Sounds like extremely low compression that the engine can’t sustain idle after everything gets warm and expands.
Try giving it some gas and holding the RPMs higher at like 2,500rpm or so after letting it idle normally for 3 mins. This way it doesn’t stall. Try to get it fully warmed up so the radiator fans come on and cycle a few times.
Assuming it hasn’t stalled on you and got completely HOT, Then proceed to floor the snot out of it to blow out some carbon and open all the intake valves. Literally full throttle redline it and let it wind back down to 2,000rpm. Rinse and repeat 10 times or so and see if it will idle on its own afterward.
Come me back and let me know the results.
It will either idle on its own or it will stall out again.
~Make sure the engine is nice and hot before you floor it.
~Make sure your fluids are all in spec before you proceed, especially the engine oil.
Get a rotary-specific compression test done to verify this.
If it is toast, you might be able to get it running again for a year or three for with a cheap/budget rebuild for $2000 - $3000.
A Mazda reman engine (with mostly new parts) will start around $3000 + tax/shipping/etc.
Regardless which way you go, you'll need to ship your old engine back or pay a core charge ($1000 for Mazda, $500-$1000 for most rebuilders). Also, add another $1000 for worn parts and incidentals. If you plan on having somebody else do all of the work to swap the motors, add at least another $1500.
,I had the same problem with my rx8. I never looked into it to much but this is what I did look into. when I checked for spark there was none. Be sure to check if your alarm is not on valet. These cars have engine shut off / engine disable features built into the factory alarms. I'm pretty sure that's what was wrong with my car. I put the alarm on valet because a friend told me it was a neat trick by turning the door lock cylinder with the key a couple of times. It did work. the alarm never went off again. how ever, if you don't put the alarm back on the alarm will think the car is being stolen and disable the engine by shutting down the spark / ignition system. the car worked fine for a couple of weeks , then it started to shut down after a few minutes of cold starting, and would never start back up. I would let the car sit over night , then start it without a problem. Then repeat the same thing. I gave up to easily and sold the car as is. I don't think its a compression problem. my car ran fine with only 95,000 original miles and no symptoms of lack of power. check all the usual problems, lack of fuel pressure, lack of spark, If the car starts everything is ok and working, compression, fuel , and spark. It could be the ignition coils getting hot and shutting down, check to make sure the computer is triggering the ignition coils. If the computer is signaling the coils there should be spark, now all you need is fuel pressure. check these items and let me know. I would have loved to fix my first baby. now I have a 2006 and I will never let her go!
One redline probably isn't enough. Looking at the limited data on rotary engines and Engineering Explained video on carbon buildup, I don't think occasional redlines can really make all the parts reach the carbon clean out temperature.
If your car refuses to idle, you can still hold it to idle at a higher RPM.
And like Brettus said, there are other possibilities, like a vacuum leak.
Last edited by UnknownJinX; Mar 11, 2019 at 02:34 PM.
Obviously a compression test is by far the best source to get health data in the engine.
Perhaps the OP can borrow even a standard compression tester (or just go buy a $30 unit, and consider it part of the diognistic expanse that you get to keep afterward as a gift) and get some numbers from the engine?
If the needle jumps 90psi, 87psi, 20psi, then you know you’ve got catastrophic failure on one side of the Rotor.
Now we are starting to make sense. I agree with doing a compression test. this will let you know if it really is a worn apex seal or not. take out the top trailing plugs and connect a standard compression tester. crank the engine a few times 80-90 psi should allow the engine to run but 125 is really good.
Did the compress test.
Got the motor up to running temperature by keeping it around 1500 to 2000 rpm.
Let off the gas motor died. As exspected.
Took out the top two plugs.
Hooked up my compression tester and this is what I got.
On the back cylinder I got 60-58-60 over and over
On the front cylinder I got 60-60-60 over and over
i don’t no how to do the conversion chart.
Really don’t no the RPM as well when cranking.
was a full battery and cranked just fine.
My guess with that low of compression motor shot.
Has about 127,000 miles
your thoughts thanks.
Possibly. I’ve just had FOUR RX-8s over the years and had one that put out 56psi-60psi @ 190rpm and although it literally had what seemed like 50hp, and ran like crap, I still daily’d it to work and back for a year without any problems of stalling once it was already running.
Had two more that were in the 70s psi. Ran fine and had no problems starting HOT. Sold them to happy buyers.
My point is, if the ignition system is fresh and all other engine components are fine, then the car should drive... technically.
The only time I had one that wouldn’t want to idle once HOT was one that had just one Rotar face put out 20psi while the rest are say... 70s.
But anyway, low compression is not a guarantee of any particular behavior, since it depends which seal is compromised, but certain behaviors, like poor hot starts/idles are symptoms of low compression.
Yeah sounds like the compression is low. when you can, just reseal the engine. A seal kit usually costs 4-5 hundred bucks. As long as the rotor housing isn't to scratched up. I have included a picture of the mazda factory manual on compression thresholds. hope this helps confirm diagnosis. here is a pic of the mazda manual on compression threshold
Yeah sounds like the compression is low. when you can, just reseal the engine. A seal kit usually costs 4-5 hundred bucks. As long as the rotor housing isn't to scratched up. I have included a picture of the mazda factory manual on compression thresholds. hope this helps confirm diagnosis. here is a pic of the mazda manual on compression threshold
One does not simply reseal the engine for 4 to 5 hundred bucks. That notion is nonsense on stilts.
A genuine seal kit actually costs around $1200. Figure another $1200 for incidentals (tools, other seals, gaskets, hoses, fluids, filters, radiator, ignition parts, etc.). A DIY job actually starts around $2400. And, that assumes you get it right the first time, which almost no one does.
One does not simply reseal the engine for 4 to 5 hundred bucks. That notion is nonsense on stilts.
A genuine seal kit actually costs around $1200. Figure another $1200 for incidentals (tools, other seals, gaskets, hoses, fluids, filters, radiator, ignition parts, etc.). A DIY job actually starts around $2400. And, that assumes you get it right the first time, which almost no one does.
do you even flex seal/jb weld bro? or just install new apex seals through the spark plug holes
